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(11) | EP 1 541 927 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Hand held lighter |
| (57) In order to provide a hand held lighter which is difficult to operate accidentally
and which is difficult for children to operate, the hand held lighter comprises a
fuel container 1 a fuel valve 9 for allowing fuel to be fed from the fuel container
to an ignition point, a lever 4 for operating the fuel valve 9, a flint 5, a rotatably
mounted sparking wheel 6 contacting the flint 5 and for generating sparks when the
sparking wheel 6 is rotated, the sparks being projected to the ignition point. The
lever has an operating surface, 10 for contacting a user's thumb or finger. The lighter
defines an operating axis A passing tangentially to the sparking wheel at X and passing
through the operating surface of the lever 4 at a point Y, at least part of the operating
surface 10 of lever being inclined outwardly with respect to the axis A. |
[0001] The present invention relates to a hand held lighter. The present invention relates particularly to a hand held lighter of the type comprising a fuel container, a fuel valve for allowing fuel to be fed from the fuel container to an ignition point, a lever for operating the fuel valve, a flint, a rotatably mounted sparking wheel contacting the flint and for generating sparks when the sparking wheel is rotated, the sparks being projected to the ignition point.
[0003] Concerns have been raised about safety relating to simple designs of hand held lighter of this type. In particular, there is a concern that a lighter of this type might be unintentionally ignited whilst being carried, causing a fire hazard. Further, there is a desire to make hand held lighters child resistant to prevent children playing with lighters accidentally creating a fire. WO97/32163 discloses a lighter with a spark wheel slip ring. The spark wheel slip ring is intended to make operation of the lighter more difficult so that accidental ignition or ignition by children is unlikely to occur. The user has to operate the lighter carefully so that the slip ring and a striking wheel are frictionally coupled together to move in concert to create a spark. The slip ring has a slot along its circumference which can engage with the flint housing to halt movement of the ring and the striking wheel assembly. The construction of this apparatus is complicated, increasing the cost of the lighter. Operation is relatively difficult even for adults. The present inventor has therefore sought a design of hand held lighter with additional safety features which is simple to construct and operate.
[0004] The present inventor has realised that conventional lighters employ a lever whose upper surface is configured so that it is easy to operate. In particular, the upper surface of the lever is conventionally designed to intercept the path of motion of the user's thumb or finger. The inventor has realised that an operating axis can be defined, which passes tangentially to the sparking wheel and passes through the lever. Whereas in conventional lighters, the surface of the lever is normal to the axis or inclined so that it faces towards the sparking wheel, the present inventor has realised that the surface of the lever may be configured so that it is inclined to the axis and facing outwards. This has the result that the user's thumb or finger is more likely to slip off the lever unless the lighter is operated with care. This reduces the likelihood of accidental operation of the lighter or operation by children.
[0005] Accordingly, the present inventor provides a hand held lighter, comprising a fuel container, a fuel valve for allowing fuel to be fed from the fuel container to an ignition point, a lever for operating the fuel valve, a flint, a rotatably mounted sparking wheel assembly contacting the flint and for generating sparks when the sparking wheel is rotated, the sparks being projected to the ignition point, the lever having an operating surface for contacting a user's thumb or finger, the lighter further defining an operating axis, passing tangentially to the sparking wheel assembly and passing through the operating surface of the lever, at least part of the operating surface of the lever being inclined with respect to the axis and facing outwards. Preferably, the operating axis defines approximately the line of motion of the front part of the user's thumb or finger when operating the hand held lighter.
[0006] The operating axis will pass tangentially to the sparking wheel and will pass through the operating surface of the lever, suitably passing through the part of the operating surface of the lever closest to the sparking wheel assembly. In general, hand held lighters of this type have the shape of an irregular prism, having substantially parallel sides which are gripped by the user. When such a hand held lighter is gripped by a user, using the fingers and thumb, the natural line of motion of the user's thumb is substantially parallel to the parallel sides of the lighter. Accordingly, the operating direction may be defined as a line which is tangential to the sparking wheel assembly and which passes through the operating surface of the lever but which is substantially parallel to the sides of the lighter or the axis of the lighter.
[0007] Suitably, at least part of the operating surface of the lever is inclined to this axis at an angle of at least 120°, preferably at least 130° and preferably at least 140°.
[0008] Typically, the lever will comprise an operating surface for contacting the user's thumb or finger, a fulcrum about which lever is pivotable and a valve operating portion for engaging the valve. For example, the valve contacting portion may comprise a portion of the lever adapted to fit underneath a projection formed on the valve or nozzle whereby, when the operating portion of the lever is depressed, the valve contacting portion of the lever is raised by pivoting the lever so that the valve is lifted by the action of the lever on the projection.
[0009] The operating surface of the lever may comprise a flat planar surface or a surface defined by different surface sections. It may comprise a curved surface.
[0010] Typically, the lever will comprise a central axis which passes at right angles to the axis of tilt of the lever. The axis of operation is a notional line which passes through the central axis of the lever.
[0011] The valve operating surface may be tilted outwardly or to either side at the point where it contacts the operating axis. For example, the user's thumb or finger may have a tendency to be deflected right, or left or simply towards the palm of the user's hand without operating the lever.
[0012] Preferably, at least half of the operating surface is inclined with respect to the operating axis, more preferably, at least two thirds of the operating surface is inclined with respect of the operating axis.
[0013] Other features of the hand held lighter of the present invention may be conventional. The fuel container may comprise a conventional tank for comprising liquid fuel, for example LPG (liquefied petroleum gas). Fuel may be fed from the container via a wick. The fuel valve may comprise a valve plug slidably movable inside a valve housing, the valve plug being urged into a closed position by resilient means and being movable to an open position for allowing fuel to be fed against the force of the resilient means. The valve plug may comprise a fuel delivery tube for allowing fuel to be fed in the open position. The fuel valve is suitably integral with a nozzle defining the ignition point.
[0014] Preferably, the flint comprises a conventional pyrophoric material. It may be formed into the shape of a rod. Resilient means may be provided for urging the rod of pyrophoric material towards the sparking wheel. Suitably, the valve, the lever, the lever fulcrum, and housing for the flint are mounted in a structure closing the end of the fuel container. The structure may comprise a bracket. The bracket suitably comprises means for pivotably mounting the sparking wheel.
[0015] The sparking wheel assembly may be of any suitable design. It may simply comprise a rotatably mounted sparking wheel. It may include further safety features. For example, it may comprise at least one rotatably mounted side wheel and a rotatably mounted sparking wheel. The side wheel may be rigidly connected to the sparking wheel and have a greater diameter than the sparking wheel. The side wheel may have a smooth surface so that it is comparatively difficult to operate. Alternatively, the sparking wheel may be rotatably mounted with respect to the side wheel so that the tendency is for the operator's thumb to rotate the side wheel without rotating the sparking wheel, unless the operator applies sufficient pressure for the soft part of the thumb or finger to also contact the sparking wheel.
[0016] A feature such as a switch or movable lever may be provided to prevent accidental operation of the lighter. Finally, a conventional windshield may be formed around the ignition point to prevent any flame being blown out by draughts.
[0017] The present invention has been described above by way of example only with reference to the accompanying drawings, in which:
DETAILED DESCIPTION OF THE DRAWINGS
[0018] Figure 1 is the schematic cross section through a hand held lighter according to the present invention.
[0019] Figure 2 is a schematic view, at an enlarged scale, of the sparking wheel assembly and operating surface of the lever.
[0020] Figure 3 is a schematic view, at a different scale to figures 1 and 2, of a different embodiment of lever according to the present invention.
DETAILED DESCRIPTION OF THE DRAWING
[0021] A hand held lighter of the present invention comprises a fuel container 1 of conventional design, for containing fuel, for example liquefied petroleum gas. The end of the container 1 is sealed by a structure which includes a housing 2 for a flint 5. Resilient means in the form of coil spring 3 are provided for urging the flint into contact with a sparking wheel 6.
[0022] The structure in the end of the fuel container 1 further comprises a bracket in which a lever 4 is pivotally mounted so that it defines an operating portion 10 for contacting a user's thumb or finger. When the lever 4 is depressed, a valve contacting portion 11 of the lever which engages underneath a projection formed at the base of a nozzle 8, lifts the nozzle 8. As a result, a fuel valve 9 is operated to allow fuel to be fed from the container 1 to an ignition point defined at the end of the nozzle 8. A windshield 7 is defined around the ignition point. In use, a user will use their thumb or finger to rotate the sparking wheel 6 (via side wheels as described further below) by moving the thumb of finger in a downward direction. This downward direction corresponds to the operating direction which is shown by the arrow A shown in figure 2. As a result, sparks are generated by the flint 5 and projected towards the ignition point. In the same downward movement of the thumb, the operating portion of the lever 10 is contacted and pressed down, so that the valve 9 is opened and fuel is fed to the ignition point. If the sparking wheel 6 and lever 4 are operated sufficiently quickly, fuel is fed to the ignition point at the same time as sparks are present, so that a flame is generated.
[0023] The sparking wheel 6 forms part of a sparking wheel assembly, being coaxially mounted with a pair of side wheels 12, mounted either side of the sparking wheel 6, which are a greater diameter than the sparking wheel 6. In use, the operator's thumb or finger will contact the outer surfaces of the side wheels 12 rather than the circumferential surface of the sparking wheel 6. The surfaces of the side wheel 12 are smoother than the outer surface of the sparking wheel 6 and there is a tendency for the user's thumb or finger to slip, making operation of the lighter more difficult. This provides an additional safety feature.
[0024] The parts of the side wheels indicated by arrow 13 which, in use, contact the user's thumb or finger are shown.
[0025] Figure 2 shows the sparking wheel assembly and the operating surface of the lever in more detail. An operating direction which generally traces the direction of movement of the user's thumb or finger is shown by arrow A. This operating direction is tangential to the outer surface of the sparking wheel at point X and passes through the point Y of the operating surface 10 closest to the sparking wheel 6. It can be seen that, at this point, the operating surface (10) is inclined with respect to the operating direction A, forming an angle which is greater than 90°. It faces outwards.
[0026] The operating surface is convexly curved. Accordingly, other parts of the operating surface of the lever are clearly inclined at a greater angle to the operating direction A. In particular, at the centre part, where the user's thumb contacts the operating surface most forcefully, the operating surface is inclined at angle of about 120° to the operating direction, giving the user's thumb a distinct tendency to the slip from the operating surface. The operating surface can be finished so that it has a relatively smooth and slippery surface. For example, there may be substantially no projections or indentations or other surface texturing to give adhesion to the user's thumb or finger. The operating surface may be made of relatively slippery material, for example a suitable metal alloy.
[0027] Figure 3 shows a different embodiment in schematic form. The operating surface 14 of the lever is defined by a straight, outwardly facing surface which forms an angle of about 120° to the operating direction A.
[0028] Again, there is a tendency for the user's thumb or finger to slip outwardly from the operating surface 14 during use. Accordingly, operation of the lighter shown in figures 1 and 2 or 3 by a child or by accident is relatively unlikely, as there will be great tendency for the user's thumb or finger to slip.
[0029] The present invention has been described above by way of example only and modifications can be made within the invention. The invention also extends to equivalents of the features described. The invention consists in any individual features described or implicit herein or shown or implicit in the drawings or any combination of any such features or generalisation of any such features or combination.
1. A hand held lighter, comprising:
a fuel container
a fuel valve for allowing fuel to be fed from the fuel container to an ignition
point,
a lever for operating the fuel valve,
a flint,
a rotatably mounted sparking wheel assembly, contacting the flint for generating sparks when the sparking wheel assembly is rotated, the sparks being projected to the ignition point, the lever having an operating surface for contacting a user's thumb or finger, the lighter further defining an operating axis, passing tangentially to the sparking wheel assembly and passing through the lever, at least part of the operating surface of the lever being inclined with respect to the axis and facing outwards.
2. A hand held lighter according to claim 1, wherein at least part of the operating surface
of the lever is inclined to the operating axis at an angle of at least 120°.
3. A hand held lighter according to claims 1 or 2, wherein the operating surface comprises
a substantially flat planar surface.
4. A hand held lighter according to claims 1 or 2, wherein the operating surface of the
lever comprises a curved surface.
5. A hand held lighter according to any preceding claim, wherein at least half of the
operating surface is inclined with respect to the operating axis.